Jean-Jacques Rousseau

His opening line in the Social Contract is also his problem statement. A person born free ends up ruled — by kings, by custom, by the wealthy who fenced the common earth and called it property. The Discourse on Inequality argues the chains were forged in steps: agriculture, ownership, then government to protect the owners.

So legitimacy cannot come from force or from God's appointment. It can only come from the ruled themselves — an agreement where each person gives all of their rights to all, and so keeps them by taking them back as a citizen.

The will of all is what everyone happens to want — private interests summed, which cancel to nothing. The general will is what the people want for the people: the aim they share once private bargaining is set aside. A law drawn from it binds everyone equally, including those who wrote it.

This is the dangerous genius of the idea. It makes sovereignty belong to the people — no assembly, monarch or corporation can own it — but it leaves open who gets to say what the general will is. Rousseau meant a people legislating for itself; the Revolution later supplied interpreters.

The same year he published the Contract he published Émile, a book-length thought experiment in raising one child without the artificial desires society drills in: let the pupil learn from things, not from words; keep him dependent on reality, not on other people's opinion. Society corrupts, but a person formed against its vanity can still be free inside it.

Read together the two books make one argument: you cannot fix politics until you understand what power does to a person, and you cannot understand a person until you remove what power added.

Every later argument about who owns the state — and who may act in its name — runs through him first.